Manufacture of thread



1940- s. w. BRAINARD MANUFACTURE THREAD Filed Aug. 11, 1932 Fig.2

VEN TOR. fagmoui Wfi/wuln cl BY I Patented Oct. 15, 1940 PATENT OFFICE.

MANUFACTURE OF THREAD v .Seymour Wilson Brainard, Kenmore, N. Y.,-as-

signor, by mesne assignments, to E. I. du Pont de Nemours & Company, Wilmington, vDel., a corporation of Delaware i Application August 11, 1932, Serial No.628, 317

11 Claims.

This invention relates to the manufacture of thread. More particularly the invention relates to the manufacture of thread of continuous filament character. Still more particularly the invention relates to animproved method of handling thread, such as regenerated cellulose rayon,

regenerated cellulose horsehair and straw, threads of other kinds such as of cellulose esters and ethers, and particularly to threads of all kinds it) which may be processed in cake form and which exhibit a tendency to shrink during treatment. The invention also relates to'an improved spinning bucket. The invention will be described in its application to the particular field of regen- 15 erated cellulose rayon as made by the viscose process, but it is to beunderstood that this particular description is not limitative of the invention. I

In the production of rayon by the viscose proc- 20 ess a viscose solution is forced through aspinneretteinto a setting bath from which it is drawn by a godet wheeland is passed into a swiftly revolving bucket whose rotation throws the thread toward the bucketwall. A traversing g mechanism, whose construction isnot essential to this application, lays the thread helically against the wall of the bucket or against the layers of thread already on the wall of the bucket.

In this way an annularbucke-t cake, which may 0 have a threadwall of about an inchin thickness,

is built.

' Following the spinning of the cake the thread is further processed in cake form or is unwound and further processed in the form of a skein.

Since handling of the thread is to be avoided as much as possible, complete processing in the cake form is desirable. This processing of the thread, whether in skein or in cake form, involves treatments with liquids to wash free of setting fiuid,

to desulphur, to bleach, to 'dye and the like for the purpose'of impartingdesirable characteristics to? the finished product. After the treatment with liquids the cake is dried. In certain of the steps of the processing and in drying the thread shrinks. This shrinkage, if the "thread be freely suspended, may be or more and is usually at least 5%." When theprocessingis carried out on the cake, there isatendency for the inner layers of thread to retard the shrinkage of the 0 outer layers. This produces a thread having varying. denier, elongation, shrinkage, tenacity, and dyeing properties. Furthermore, when this yarn is used in the textile industry and is wetted and dried, the shrinkage is again variable be- 55 cause part of utheflyarn has shrunk. substantially its full amount and part is capable of additional shrinkage.

- It is an object ofthis invention to prepare a bucket cake which canbe quickly, uniformly, and thoroughly processed without unwinding, 5 i and to produce by bucket spinning and bucket cake treatment a'yarn having substantially uniform characteristics, Another object of the invention is to produce an apparatus capable of forming a bucket cake which may be treated as 1 such without producing yarn of varying characteristics. Other objects of the invention will be in part apparent and in part set forth in the following description. i

The objects of the invention are accomplished by spinning a bucket cake in which the circumference of an inner winding differs from the circumference of the adjacent outer winding by an amount expressed by the formula: X Y(Z+V) where Xis the circumference of an. inner winde ing, Y is the circumference of an. outer Winding, Zis the amountwhich an inner winding in a truly circular bucket would difier from the adjacent outer winding, and V is an additional amount. The objects of the invention are accomplished, in the preferred embodiment of the invention, by theuse of a bucket having a sinuous inner, wall. The objects of the invention are accomplished more particularly by spinning a bucket cake having a circumference, enlarged by axially alined depressions of projections, longer than the circumferenceof a circle of equal radius.

In the drawing, Figure 1 is a plan view of a cross-section on the lineII of Figure 2; Figure 2 is a vertical cross-section on the line IIII of Figure 1; Figure 3 is a plan view of a modified form of bucket; Figure 4 is a diagrammatic representation of the preferred form of cross-section for the bars; Figure 5 is a modified form of bar; and Figure 6 is still another form of bar.

Referring now to the numerals on the drawing, I0 is a bucket; II are integral bar-like projections on the interior of the bucket placed approximately parallelto the axis of rotation and 4 having a surface preferably, but not necessarily, in the form of a smooth curve; i2 is a bucket cover. Buckets of this type may be moulded, cast, ma'chinedor formed by any other suitable process.

In Figure 3 is shown a modified form of the invention. In this figure the bar-like projections are not integral with the bucket but are attached to an ordinary bucket by any suitable means. This figure also represents the fact that the number of bars is not of the essence of the invention.

Figure 4 shows a bar whose shape is preferred because it reduces looping of the thread to a minimum. Figures 5 and 6 show successful modified bar shapes.

In the form of the invention wherein an ordinary spinning bucket is modified toform an irregular cake, I prefer to use members of the shape shown in Figure 4. These members may be made of wood, rubber, Bakelite, casting aluminum, or some suitable alloy such as Woods metal, or of any other material which is capable of being formed to the desired shape and of resisting treating liquids. These members or bars are carefully fitted into position so as to preserve the balance of the bucket and to form a tight joint with the inner surface of the bucket. A suitable protective coating may be applied to the bucket interior to prevent damage to the yarn and infiltration of treating liquids beneath the bar. Examples of such coatings are rubber compositions, coating compositions resistant to the process liquids, layers of resistant metals and the like.

A cake formed in my bucket follows the contour of the bucket until a reasonably large cake has been built up, after which the inside gradually takes the form shown by the dotted line in Figure 1. By proper selection of the number, size, and shape of the sinuosities the shrinkage of the thread can be made substantially uniform throughout the cake.

The embodiments of my invention are capable of many modifications: The sinuosities can take the form of depressions in the side wall of the bucket rather than the form of raised members. The number, size, and location of the sinuosities or sinuosity-producing elements can be arranged to suit the needs of the particular process although, due to the high speeds at which the buckets revolve, best results will be secured by arranging the sinuosity-producing elements in balanced relation. The bars, or their equivalent in a molded bucket or liner, may be roughened to prevent the thread from slipping. Instead of using a molded bucket or of inserting bars in an ordinary bucket, a liner having an inner periphery constructed in accordance with the principles of this invention may be made, as by molding or casting, and fitted into the ordinary bucket. The size of the sinuosity-producing elements need not be the same and the sinuosity-producing elements need not be uniformly arranged so long as their arrangements meet the requirement of balance. The bars may be hollow when by the use of that construction a lighter weight will be advantageous. The bars or elements, due to the flare of the usual bucket, are not precisely parallel to its axis of rotation. Furthermore, the bars may be placed at an angle to a geometrical element of the bucket.

The invention has been described in its application to the spinning of rayon, but it is applicable to the spinning or winding of any thread and has particular advantage where the thread is contractible.

An advantage of my invention is in the production of thread of improved uniformity by the process involving treatment of the thread in cake form. Another advantage of my invention is in improving the permeability of bucket cakes, in shortening the time needed for treatment of the cake, in lessening the quantity of materials required for treatment. For instance, cakes have been spun under identical conditions from the same viscose solution according to standard methods and in accordance with this invention, respectively, and where the standard cake required upward of twenty-five hours for washing free of acid, the cake spun according to my invention was Washed free of acid in six hours. Another advantage of the invention is in substantially overcoming undesirable shrinkage effects during the several steps of cake treatment and in the production of yarn which is approximately physically uniform without resort to the skein process. By this invention an easily processed cake is produced even at bucket speeds which produce by prior art processes cakes too impermeable to treat successfully in cake form. Other advantages of the invention will be apparent.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. A bucket cake in which the circumference of an inner winding differs from the circumference of an adjacent outer winding by an amount represented by the formula: X=Y(Z-|-V) where X is the circumference of an inner winding, Y is the circumference of an outer winding, Z is the amount which an inner winding in a truly circular bucket would, differ from an outer winding, and V is an additional amount, the differences in circumferences between the windings in the cake being sufiicient to introduce slack throughout all portions of the cake wherein resistance to contraction would otherwise occur, whereby when the cake is formed and dried substantially uniform shrinkage is obtained.

2. In an apparatus for spinning artificial silk a centrifugal spinning pot for collecting freshly spun artificial silk thread in package form, the said. spinning pot having an inner surface provided with inwardly projecting portions of such conformations as to produce a corrugated endless inner embracing wall, the said corrugations being of sufficient size and shape to introduce slack throughout all parts of the thread package wherein resistance to contraction would otherwise occur whereby when the package is formed and dried, uniform shrinkage is produced.

3. In a bucket spinning machine for the production of artificial filaments or threads, a spinning bucket having irregular thread-contacting surfaces, the irregularities being of sufiicient size and shape to introduce slack throughout all portions of a cake wherein resistance to contraction would otherwise occur, whereby when the package is formed and dried substantially uniform shrinkage is obtained.

4. In a bucket spinning machine for the production of artificial filaments or threads, a spinning bucket having a sinuous thread-contacting wall, the sinuosities being of sufficient size and shape to introduce slack throughout all portions of the cake wherein resistance to contraction would otherwise occur, whereby when the cake is formed and dried substantially uniform shrinkage is produced.

5. In a bucket spinning machine for the production of artificial filaments or threads, a spin ning bucket having bars attached to its threadcontacting wall, said bars being of sufficient size and shape to introduce slack throughout all portions of the cake wherein resistance to contraction would otherwise occur, whereby when the cake is formed and dried substantially uniform shrinkage is produced.

6. In a bucket spinning machine for the production of artificial filaments or threads, a spinning bucket having bars attached to its threadcontacting wall and disposed approximately parallel to the axis of rotation of the bucket, said bars having smooth-curved outer surfaces, said bars being of sufiicient size and shape to introduce slack throughout all portions of the cake wherein resistance to contraction would otherwise occur, whereby when the cake is formed and dried substantially uniform shrinkage is produced.

7. In a bucket spinning machine for the production of artificial filaments or threads, a spinning bucket having projections on its threadcontacting wall, said projections being of sufficient size and shape to introduce'slack throughout all portions of the cake wherein resistance to contraction would otherwise occur, whereby when the cake is formed and dried substantially uniform shrinkage is produced.

8. In a bucket spinning machine for the production of artificial filaments or threads, 2. spinning bucket having integral bar-like members spaced about its thread-contacting periphery and disposed approximately parallel to the axis of rotation of p the bucket, said members being of sufficient size and shape to introduce slack throughout all portions of the cake wherein resistance to contraction would otherwise occur, whereby when the cake is formed and dried substantially uniform shrinkage is produced.

9. In a bucket spinning machine for the production of artificial filaments or threads, a spinning bucket having thread-contacting depressions in its inner wall and disposed approximately parallel to the axis of rotation of the bucket, said depressions being of sufficient size and shape to introduce slack throughout all portions of the cake wherein resistance to contraction would otherwise occur, whereby when the cake is formed and dried substantially uniform shrinkage is produced.

10. In an apparatus for use in the manufacture of artificial filaments or threads, a bucket adap ed to receive a cake of artificial filaments or threads having slack throughout all portions thereof wherein resistance to contraction would otherwise occur whereby, when the cake is dried, substantially uniform shrinkage is obtained, said bucket having irregular surfaces provided on its inner wall adapted to contact the outer peripheral wall of said. cake, the irregularities being of sufficient size and shape to substantially maintain said slack.

11. In an apparatus for use in the manufacture of artificial filaments or threads, a bucket adapted to receive a cake of artificial thread having a sinuous outer circumferential wall sufficient to impart slack throughout all parts of the cake wherein resistance to contraction would otherwise occur whereby, when the cake is dried, substantially uniform shrinkage is obtained, said bucket having an inner sinuous wall adapted to contact the said sinuous wall of the said cake, the sinuosities of said bucket wall being of sufficient size and shape to substantially maintain said slack in said cake.

SEYMOUR WILSON BRAlNARD. 

